allow static export on master

Author: cometkim

next.config.mjs

@@ -14,6 +14,7 @@ const { ProvidePlugin } = webpack;
 const transpileModules = ["rescript"].concat(bsconfig["bs-dependencies"]);
 
 const config = {
+  output: process.env.BUILD_STATIC === 'true' ? 'export' : undefined,
   pageExtensions: ["jsx", "js", "bs.js", "mdx", "mjs"],
   env: {
     ENV: process.env.NODE_ENV,